The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

May and Sturgeon set for Brexit showdown

British Prime Minister Theresa May has warned lawmakers not to obstruct the will of the British people with a series of amendments to her Brexit legislation.

"Our European partners now want to get on with the negotiations, so do I, and so does this house," May told parliament.

"The message is clear to all, this house has spoken and now is not the time to obstruct the democratically expressed wishes of the British people. It is time to get on with leaving the European Union."

May can have her wish but the news has been met with opposition by the devolved Scottish government who are planning to underscore their displeasure with May by rejecting Brexit.

Scottish leader Nicola Sturgeon, who says Scotland must have a choice on holding a new independence referendum that could break the United Kingdom apart, has repeatedly demanded that the interests of Scotland be taken into account during the Brexit negotiations.

A motion presented by the Scottish government will argue that the triggering of Article 50 should be rejected because the British government has left too many questions unanswered and that the Westminster parliament is not guaranteed a say in any new trade relationship once Britain has left the EU.

Lawmakers in the devolved assembly in Edinburgh will be asked to agree that May's Brexit bill should be stopped because London has not set out provisions for reaching a UK-wide approach with devolved administrations on Brexit.